Generator regulator / alternator

Thread Starter


Joined Apr 9, 2009

I'm trying to teach about energy conversion, and to make it as hands on as possible. I want to have kids push a pedal or bike powered generator, have it power different loads, and feel the drag from the load.

There's a nicely designed "human powered generator" which puts out 12V DC, but that can vary with the speed of the human. I can easily put an incandescent bulb on it, and I expect you'd feel the drag of pushing through that kind of load.

Then I want to power other stuff. I found 12V CFLs, but I'd rather not be stuck in the 12v regime. I want to be able to plug in a 120v device, like a small tesla coil (to safely light a fluorescent tube) or an ipod or whatever. I want to make it relevant to what people see every day.

Two questions:

1) How can I make a simple voltage regulator that can keep output below 12v, up to 35 watts or so.

2) How can I turn 12v DC (with lots of variation) into 12v AC? I wish I could use an off-the-shelf AC inverter, but they all have safety shut offs on low voltage. The point is that I'd want the person pedaling to feel the drag as the load increases.

Thanks so much for your advice!